Luis María Argaña

However, on the morning of March 23, 1999, assailants ambushed the vice president's vehicle just outside his Asunción home, peppering the SUV with multiple rounds of gunfire before escaping. President Cubas ordered a lockdown of the country's borders. In the wake of the killing and the subsequent riots that took place in the capital area, Cubas' support melted away. The Chamber of Deputies impeached him by an overwhelming margin. Facing all-but-certain conviction and removal from office by the Senate, Cubas resigned on March 28, fleeing the country and seeking and ultimately being granted political asylum in neighboring Brazil. Senate president Luis Ángel González Macchi, who was next in line for the presidency after Argaña's death, served out the balance of Cubas' term.

On October 23, 1999, Pablo Vera Esteche was arrested in Paraguay. He said the murder, for which he and two other gunmen were paid a total of $300,000, was authorised by Cubas and Oviedo. Vera Esteche was sentenced to 20 years on October 24 (reduced to 18 years four years later). His accomplices were also jailed for lengthy sentences.

He tried again to obtain the party's presidential nomination for the 1998 election, losing in a bitterly contested primary election against General Lino Oviedo. Due to the General's involvement in a failed coup attempt in 1996, Oviedo was imprisoned before the 1998 general election. Oviedo's running mate, Raúl Cubas, replaced Oviedo on the Colorado ticket, but lacked the widespread support that Oviedo commanded. Argaña was selected as Cubas' running mate, the pair subsequently being elected to office by a wide margin.

Luis Argaña served in a number of important national positions during previous administrations before running an ultimately unsuccessful bid for president in the 1993 election. He publicly vowed that if elected, he would allow Stroessner to return from exile. Although leading opinion polling at one point, he lost the Colorado Party primary to Juan Carlos Wasmosy who went on to win the first completely free election in the country's history.

Argaña was a judge during Paraguay's long-lasting military dictatorship under Alfredo Stroessner. He has been accused of turning a blind eye to cases of torture and political killings. Stroessner dissident Joel Filártiga accused Argaña of blocking the screening in Paraguay of the 1991 TV movie One Man's War, depicting Filártiga's search for justice for the 1976 death of his son at the hands of Stroessner's secret police.

Argaña graduated in law and social sciences from the Universidad Nacional de Asunción in 1958. He became a Professor at the University, and entered politics, becoming a member of the Chamber of Deputies of Paraguay. He also became a judge, and was President of the Supreme Court of Paraguay (1983 - 1988).

Luis María del Corazón de Jesús Dionisio Argaña Ferraro (October 3, 1932 – March 23, 1999) was a prominent Paraguayan politician and Supreme Court judge. He was an influential member of the Colorado Party and rose to the Vice-Presidency in 1998, but was assassinated in March 1999 at a time when it appeared likely that he would inherit the presidency from Raúl Cubas, who was on the verge of being impeached. The incident and its aftermath is known in Paraguay as Marzo paraguayo ("the Paraguayan March"). An airport in Paraguay, Dr. Luis María Argaña International Airport, is named for him.